Direction: A 10 mm diameter annealed steel wire is drawn through a die at a speed of 0.5 m/s to reduce the diameter by 20%. The yield stress of the material is 800 MPa.
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Neglecting friction and strain hardening, the stress required for drawing (in MPa) is
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- 178.6
- 357.0
- 1287.5
- 2575.0
Correct Option: B
Diameter of steel wire
di = 10 mm
v = 0.5 m/sec
Final diameter of wire
df = 0.8 × di = 8 mm
(drawing stress)
| σd = σyt × ln |  | di |  | ² | ||
| df |
| = 800 × 2ln | | 10 | | = 357 MPa | ||
| 8 |
